HTTP/2 200
content-type: text/html
x-guploader-uploadid: ABgVH8-VgGnFeTecMQgkGMLSHWZXGNexhrla711bge3Pj7z-M8UylFjm3Bo4ZladHxWklspA
cache-control: public, max-age=3600
expires: Tue, 15 Jul 2025 07:50:09 GMT
last-modified: Tue, 15 Jul 2025 00:46:42 GMT
etag: W/"d324c819384ce55eb119467bc8472a61"
x-goog-generation: 1752540402412439
x-goog-metageneration: 1
x-goog-stored-content-encoding: identity
x-goog-stored-content-length: 125139
x-goog-meta-goog-reserved-file-mtime: 1752539134
x-goog-hash: crc32c=FwmufQ==, md5=0yTIGThM5V6xGUZ7yEcqYQ==
x-goog-storage-class: STANDARD
accept-ranges: none
alt-svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
alt-svc: clear
x-content-type-options: nosniff
strict-transport-security: max-age=63072000
content-security-policy: default-src 'self'; script-src 'report-sample' 'self' 'wasm-unsafe-eval' https://www.google-analytics.com/analytics.js https://www.googletagmanager.com/gtag/js assets.codepen.io production-assets.codepen.io https://js.stripe.com 'sha256-EehWlTYp7Bqy57gDeQttaWKp0ukTTEUKGP44h8GVeik=' 'sha256-XNBp89FG76amD8BqrJzyflxOF9PaWPqPqvJfKZPCv7M='; script-src-elem 'report-sample' 'self' 'wasm-unsafe-eval' https://www.google-analytics.com/analytics.js https://www.googletagmanager.com/gtag/js assets.codepen.io production-assets.codepen.io https://js.stripe.com 'sha256-EehWlTYp7Bqy57gDeQttaWKp0ukTTEUKGP44h8GVeik=' 'sha256-XNBp89FG76amD8BqrJzyflxOF9PaWPqPqvJfKZPCv7M='; style-src 'report-sample' 'self' 'unsafe-inline'; object-src 'none'; base-uri 'self'; connect-src 'self' developer.allizom.org bcd.developer.allizom.org bcd.developer.mozilla.org updates.developer.allizom.org updates.developer.mozilla.org https://*.google-analytics.com https://*.analytics.google.com https://*.googletagmanager.com https://incoming.telemetry.mozilla.org https://observatory-api.mdn.allizom.net https://observatory-api.mdn.mozilla.net https://api.github.com/search/issues stats.g.doubleclick.net https://api.stripe.com; font-src 'self'; frame-src 'self' interactive-examples.mdn.mozilla.net interactive-examples.mdn.allizom.net mdn.github.io live-samples.mdn.mozilla.net live-samples.mdn.allizom.net *.mdnplay.dev *.mdnyalp.dev *.play.test.mdn.allizom.net https://v2.scrimba.com https://scrimba.com jsfiddle.net www.youtube-nocookie.com codepen.io survey.alchemer.com https://js.stripe.com; img-src 'self' data: *.githubusercontent.com *.googleusercontent.com *.gravatar.com mozillausercontent.com firefoxusercontent.com profile.stage.mozaws.net profile.accounts.firefox.com developer.mozilla.org mdn.dev interactive-examples.mdn.mozilla.net interactive-examples.mdn.allizom.net wikipedia.org upload.wikimedia.org https://mdn.github.io/shared-assets/ https://mdn.dev/ https://*.google-analytics.com https://*.googletagmanager.com www.gstatic.com; manifest-src 'self'; media-src 'self' archive.org videos.cdn.mozilla.net https://mdn.github.io/shared-assets/; child-src 'self'; worker-src 'self';
x-frame-options: DENY
origin-trial: AxVILwizhbMjxFeHOn1P3R8niO1RJY/smaK4B4d1rLzc1gTaxtXMSaTi+FoigYgCw40uFRDwFcEAeqDR+vVLOW4AAABfeyJvcmlnaW4iOiJodHRwczovL2RldmVsb3Blci5tb3ppbGxhLm9yZyIsImZlYXR1cmUiOiJQcml2YXRlQXR0cmlidXRpb25WMiIsImV4cGlyeSI6MTc0MjA3OTYwMH0=
x-cloud-trace-context: 553e2fbd9a352e93dcac0941ef3b5cd6
date: Tue, 15 Jul 2025 06:50:09 GMT
server: Google Frontend
via: 1.1 google
vary: Accept-Encoding
content-encoding: gzip
x-cache: miss
Baseline - Glossary | MDN
The term baseline can have several meanings depending on the context. It may refer to:
Baseline (compatibility) Baseline identifies the availability of web platform features across popular browsers, including APIs, CSS properties, and JavaScript syntax. Baseline describes web features as being either widely available or newly available. Features that do not meet the Baseline criteria are said to have limited availability.Baseline (typography) A baseline is an imaginary line along the inline axis of a line box along which individual glyphs of text are aligned. Baselines guide the design of glyphs in a font and the alignment of glyphs from different fonts or font sizes when typesetting.